High-pressure and high-temperature multiplunger apparatus

ABSTRACT

In the proposed apparatus, each plunger shaped as a truncated pyramid is provided with grooves extending along the edges of the smaller base of the pyramid and forming circular passages round a working chamber in the gaps between adjacent plungers. The cross section of each passsge is defined by smooth curves, the passages being filled with a sealing material. In each gap between plungers, there may be provided a plurality of parallel passages which, in some cases, are filled with materials of different compressibility.

United States Patent [1 1 Vereschagin et a1.

[ Oct. 28, 1975 HIGH-PRESSURE AND HIGH-TEMPERATURE MULTIPLUNGER APPARATUS Inventors: Leonid Fedorovich Vereschagin,

Filed:

Kutuzovsky prospekt, 2/1, kv. 231; Aik Akopovich Semerchan, Kutuzovsky prospekt, 2/1, kv. 205, both of Moscow; Nikolai Nikolaevich Kuzin, Podolsky raion, Akademgorodok, ulitsa Shkolnaya, 4, kv. 38; Jury Alexandrovich Sadkov, Podolsky raion, Akademgorodok, ulitsa Tsentralnaya, 10, kv. 43, both of Moskovskaya oblast, all of U.S.S.R.

Oct. 11, 1974 Appl. No.: 514,217

US. Cl 425/77; 425/DIG. 26 Int. Cl. B30B 11/32 Field of Search 425/77, DIG. 26

[56] References Cited UNITED STATES PATENTS 2,947,034 8/1960 Wentorf 425/77 3,137,896 6/1964 Daniels 425/77 3,328,838 7/1967 Zeitlin .Q. 425/77 3,790,322 2/1974 Sirota et .al. 425/77 3,854,854 12/1974 Vereschagin et a1. 425/D1G. 26

Primary Examiner-l Howard Flint, Jr. Attorney, Agent, or FirmI-Iolman & Stern [5 7] ABSTRACT In the proposed apparatus, each plunger shaped as a truncated pyramid is provided. with grooves extending along the edges of the smaller base of the pyramid and forming circular passages round a working chamber in the gaps between adjacent plungers. The cross section of each passsge is defined by smooth curves, the passages being filled with a sealing material. In each gap between plungers, there may be provided a plurality of parallel passages which, in some cases, are filled with materials of different compressibility.

4 Claims, 1 Drawing Figure US. Patent Oct. 28, 1975 HIGH-PRESSURE AND HIGH-TEMPERATURE MULTIPLUNGER APPARATUS BACKGROUND OF THE INVENTION temperature multiplunger apparatus wherein the working chamber is shaped as a regular polyhedron defined by the end faces of plungers made in the form of truncated pyramids spatially arranged in such a manner that the axes thereof cross at a common center point.

In the initial state, a small gap is provided between the lateral sides of the plungers, thereby enabling the plungers to move along their axes towards said common center point under the action of forces applied thereto, as a result of which compression of the contents of the working chamber is achieved. The rate of compression of the contents of the working chamber, hence, the magnitude of the pressure built up in the working chamber of said known apparatus, is determined by the thickness of the packing which ensures reliable sealing of the working chamber rather than by the closest possible distance between the plungers as they are brought together.

In the prior art apparatus, said packing is formed, as the plungers come closer to one another, by the material of the specimen holder and is extruded from the working chamber into the gap between the lateral sides of the plungers. Reliable sealing of the working chamber by such packing can only be ensured if the packing is extremely thin (a few tenths of a millimeter), which can only be achieved when the plungers are finally brought together. The small thickness of the packing limits the rate of compression of the contents of the working chamber, hence, the magnitude of the pressure built up therein. This limitation is especially important in apparatus having larger working chambers, in which case it involves a possible decrease in pressure due to the large volume of the working space. Moreover, a sharp difference between the pressure within the working chamber and atmospheric pressure always occurs in the material of said packing and that of the plunger contacting the packing. This is one of the main causes of destruction of the plungers and unstable op eration of the apparatus, especially under the combined action of high pressures and temperatures, which results in an explosive expulsion of the contents of the working chamber.

SUMMARY AND OBJECTS OF THE INVENTION It is an object of the present invention to provide a multiplunger apparatus with the possibility of increasing the pressure of its working chamber and improving the reliability and stability of its operation.

Another object of the invention is to provide a highpressure and high-temperature multiplunger apparatus with a higher upper pressure limit within a preset volume of its working chamber, as compared to those attainable in the prior art apparatus of this type.

Yet another object of the invention is to provide a multiplunger apparatus of a design which would ensure reliable and stable operation of the apparatus under high pressures.

Still another object of the invention is to provide a high-pressure and high-temperature multiplunger apparatus with the possibility of improving its performance by efficient and easily realizable means.

With these and other objects in view, according to the present invention, a high-pressure and hightemperature multiplunger apparatus having plungers shaped as truncated pyramids whose smaller bases are brought close to one another in the course of operation, confining thereby within the apparatus a working chamber of polyhedral shape, is provided with grooves made in the lateral sides of the plungers adjoining the smaller base of a pyramid, said grooves extending along the edges of the smaller base of each pyramid and forming in anassembled condition of the apparatus, circular passages filled with a sealing plastic electric insulation material.

This feature makes it. possible to substantially increase the pressures built up in the working chamber by obstructing the extrusion of the compressed material through the gap between the plungers as well as by improving the supporting ability of the material of the plungers aided by the pressure in the sealing material.

According to an alternative embodiment of the pres ent invention, said grooves extend parallel to the edges of the smaller bases of said pyramids so that the crosssection of the passage formed by the grooves of adjacent plungers are defined by smooth curves.

This feature, according to the invention, ensures smooth extrusion of the sealing material with a gradual reduction of the pressure therein from the operating level to that of atmospheric pressure.

A multiplunger apparatus, in accordance with another embodiment of the invention, is characterized in that a plurality of parallel passages are provided between adjacent plungers with the narrow portions of the gaps between the passages of said plungers of different widths.

This feature of the apparatus according to the invention makes it possible to utilize the properties of the sealing materials which are normally characterized by poor plasticity by increasing their plasticity in the course of compression as one material is supported by another, filling the adjacent passage successively farther from the working chamber.

According to yet another embodiment of the present invention, a multiplunger apparatus is featured by the passages defined by adjacent pyramidal plungers 'in each gap therebetween being filled with sealing materials of different compressibility and coefficients of internal friction; the coefficient of internal friction of the sealing material decreasing as the distance from the working chamber increases.

And, finally, according to one more embodiment of the multiplunger apparatus according to the invention, smoother extrusion of the sealing material through the gaps between the pyramidal plungers can be attained.

BRIEF DESCRIPTION OF THE INVENTION The present invention will be more apparent from the following detailed description of an embodiment thereof with reference to the accompanying drawing, which shows a cross-sectional view of a high-pressure and high-temperature multiplunger apparatus, according to the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT A high-pressure andhigh-temperature apparatus according to this invention has a working chamber I shaped as a regular polyhedron formed by the smaller bases of plungers 2 made as truncated pyramids and spatially arranged in such a manner that the axes thereof intersect at a common center point. The number of the plungers 2 of the apparatus is determined by .the required number of sides of the polyhedral working chamber 1.

The drawing illustrates an apparatus having its work- I ingchamber shaped as a cube and, respectively, provided with six pyramidal plungers 2, only four being shown. Grooves 3 made in the lateral sides of the plungers 2 have their generatrices parallel to the bases of the plungers 2. The grooves 3 are partially or comperiphery of the apparatus through gaps A and B between projections on the lateral sides of adjacent plungers 2. The pressure developed at this moment within-the material of each inner packing strip 4 depends on the pressure within the adjacent outer packing 5 .disposed closer to the periphery and receiving therein the extruded material of the packing 4. Additionally, the width of the gaps A or B between the projections on the lateral sides of adjacent plungers 2, which gaps permit the material of a respective packing to .be extruded therethrough, help to determine the pressure within packing strip 4.

By adjusting the width of the gaps A and B and by selecting adequate materials for the packings 4,5, it is possible to attain within the packing 4, directly contacting the working chamber 1, a pressure ensuring reliable sealing of. the working chamber 1 as the hard-alloy plungers 2 start coming close to one another, instead of at the end of the compression stroke as is .the case in the prior-art apparatus. Thus, in the apparatus according to the present invention, a higher rate of compression of the working chamber contents can be achieved and, hence, higher pressures can be attained as compared with the conventional multiplunger apparatus of this kind.

Decreasing the pressure from its operating level to atmospheric, through the packings 4 and 5 with a relatively small pressure gradient, ensures an effective support of the material of the plungers 2, the latter being capable, as a result, of withstanding a higher pressure in the working chamber without destruction. At the same time, there is ensured an improved stability in operation of the apparatus under the increased pressures in combination with high temperatures. The working chamber 1 is sealed by one or several rows of the packing 4,5 depending on the pressure desired therein.

The multiplunger apparatus according to the present invention, in distinction from the conventional ones, makes it possible to obtain within a working chamber having a volume of more than 200 cm,- a pressure and a temperature high enough to effect the synthesis of polycrystalline diamond formations of the Carbonado type (pressure: kbar).

Some argillaceous materials with a coefficient of internal friction of 0.2-0.4 may be used as the sealing material.

The most widely used of these materials at present are the algatic stone (katlinite) and pyrophyllite both in the form of blocks and compositions of various materials based on their powder.

The smooth shape of the cross-sectional area of the grooves provided on the lateral sides of the pyramidal plungers 2 enables the pressure within the sealing material to be gradually lowered in the direction away from the working chamber of the apparatus to the periphery thereof and thereby provides for a smooth outflow of the sealing material as the plungers 2 are coming close to one another.

The extent of support during extrusion of the selected sealing material depends, mainly, on the width of the gaps A and B between the projections on the lateral sides of the adjacent plungers 2. The extent of support for a particular sealing material in each case should not be below a preset value ensuring the required plasticity of the sealing material.

It should be noted that the required smooth decrease in pressure change within the sealing material from the operating level to atmospheric may be attained in a rather simple way by filling the passages formed between the lateral sides of adjacent pyramidal plungers with various sealing materials having different compressibility characteristics and coefficients of internal friction, whereby, in accordance with the distance of the scaling material from the working chamber, the coefficient of internal friction thereof is decreased.

What is claimed:

1. A high pressure and high temperature multiplunger apparatus comprising:

a plurality of plungers shaped as truncated pyramids each having a base, a plurality of lateral sides each at acute angles to the base, and a face smaller than the base at the opposite end of the lateral sides from the base, said smaller faces of the plungers being brought close to one another in the course of operation to define a working chamber of polyhedral shape;

portions of each plunger defining grooves extending along said lateral sides thereof adjoining said smaller face, said grooves forming in an assembled condition of the apparatus perimetrical passages; and

a sealing plastic insulation material filling said grooves.

2. The multiplunger apparatus of claim 1, wherein said grooves extend parallel to the edges of said smaller faces of said pyramids and the cross-section of the passage formed by the grooves of adjacent plungers being defined by smooth curves.

3. The multiplunger apparatus of claim 2, wherein a plurality of parallel passages are provided between adjacent plungers, with the narrow portions of the gaps between passages of said plungers being of different widths.

4. The multiplunger apparatus of claim 3, wherein the passages defined by adjacent pyramidal plungers in each gap therebetween are filled with sealing materials of different compressibilities and coefficients of internal friction; the coefficient of internal friction of the sealing material decreassing as the distance from said working chamber increases. 

1. A high pressure and high temperature multiplunger apparatus comprising: a plurality of plungers shaped as truncated pyramids each having a base, a plurality of lateral sides each at acute angles to the base, and a face smaller than the base at the opposite end of the lateral sides from the base, said smaller faces of the plungers being brought close to one another in the course of operation to define a working chamber of polyhedral shape; portions of each plunger defining grooves extending along said lateral sides thereof adjoining said smaller face, said grooves forming in an assembled condition of the apparatus perimetrical passages; and a sealing plastic insulation material filling said grooves.
 2. The multiplunger apparatus of claim 1, wherein said grooves extend parallel to the edges of said smaller faces of said pyramids and the cross-section of the passage formed by the grooves of adjacent plungers being defined by smooth curves.
 3. The multiplunger apparatus of claim 2, wherein a plurality of parallel passages are provided between adjacent plungers, with the narrow portions of the gaps between passages of said plungers being of different widths.
 4. The multiplunger apparatus of claim 3, wherein the passages defined by adjacent pyramidal plungers in each gap therebetween are filled with sealing materials of different compressibilities and coefficients of internal friction; the coefficient of internal friction of the sealing material decreassing as the distance from said working chamber increases. 